Pedicle screws allow spine surgeons to attach rods or plates to the thoracic and lumbar spine. This rigidly immobilizes the spine segments, promoting the bone graft to grow into a fusion, welding spinal segments into one solid unit, reducing pain and stabilizing deformity.
Three types of deformity that spinal surgeons attempt to correct with regularity are Scoliosis, Spondylolisthesis, and Kyphosis, or flat back syndrome. Actual manipulation of the spine and correction of these thoracic and lumbar deformities is accomplished by distraction or compression of the points of attachment to the spine. Points of attachments are generally either hooks underneath the lamina, hooks under the pedicles or pedicle screws.
While many different pedicle screws have been developed, presently the pedicle screw is not considered a navigational point of attachment to the spine, nor have the prior art systems allowed for the attachment of the fixation hardware without first removing the alignment rods or cages.
For example, Krag, U.S. Pat. No. 5,219,349, which is incorporated herein by reference, discloses a method of aligning vertebral bodies utilizing a stabilization cage, but does not provide a system for attaching the fixation hardware to the pedicle screw while the alignment cage is in place. Likewise, Bernstein, U.S. Pat. No. 6,004,322, which is incorporated herein by reference, discloses a cannulated pedicle screw design utilized to fix the spine, but also does not provide a system for attaching alignment rods or for attaching fixation hardware while such alignment rods are in place.
With these current systems, the surgeon must remove the alignment device prior to securing the fixation hardware, allowing the vertebral bodies time to return to their improper original alignment. Accordingly, a need exists for a system and apparatus that allows a surgeon to accurately manipulate and align vertebral bodies and to enable the installation of a fixation system while such alignment devices are still in place.